The answer to this question is “it depends.” When it depends on is whether the accuser was taking his medications at the time the offense allegedly occurred and whether the accuser was taking his medications at the time he made his accusation.
I’m handling a case right now in which the accuser has a long history of mental illness. I’m not talking about mental illness in the sense of simple depression or even post-traumatic stress disorder. I’m talking about mental illness in the sense of a paranoid schizophrenic who has delusions that the president of the United States has spoken with the accuser and told him he can do all kinds of bizarre things.
Getting a case such as this thrown out takes effort. It is a simple fact that it is easier for the prosecutor to get hold of your confidential psychiatric or medical records than it is for the defense lawyer to get hold of the confidential psychiatric or medical records of the accuser. That may not be fair, but that’s the way it is.
The other important piece to this is what is the context of the wild comments that the mentally ill accuser has made in the past?
If the accuser has said such things as “there are men just outside the house with machine guns waiting to shoot me if I leave the house,” then that is obviously helpful in an assault case.
I’ve had other assault cases in which the accuser was not only mentally ill, but also was assaultive. In one particular case, I interviewed a witness who had recently been assaulted by the alleged victim in my case. She came to my office with her mother, so I left the room and let her mother take photographs of her injuries. Once I showed witness statements that I had taken and the photographs to the prosecutor, the prosecutor dismissed the case in the interests of justice.